How to baseline project for subsequent releases

[msenin]

Please help me, CVS beginner, on this:
For every release we build, we need to know which version of which
file went into release.

How do we do that with CVS?

I believe task can be simplified if we tagged all files with same
version name for every release, but we'd preffer not to change
versions of files that haven't been modified.

Thanks a lot,
Maxim